pg_attrdef

The pg_attrdef table stores column default values. The main information about columns is stored in pg_attribute. Only columns that explicitly specify a default value (when the table is created or the column is added) will have an entry here.

Table 1. pg_catalog.pg_attrdef

column

type

references

description

adrelid

oid

pg_class.oid

The table this column belongs to

adnum

smallint

pg_attribute.attnum

The number of the column

adbin

text

The internal representation of the column default value

adsrc

text

A human-readable representation of the default value. This field is historical, and is best not used.